90 Loomis, Procellaria alba Gmelin. [j" n 



Streets, U. S. N., on Christmas Island, Fanning group, in January, 

 1873, and identified by Dr. Coues and Mr. Ridgway as ' ^strelata' 

 ■parvirostris (Peale), 1 the type specimen of which was at hand for 

 comparison. 



Below is an abridged description of the two Christmas Island 

 specimens : 



Length of the skins about 14.4 inches; length of commissure 

 fully 1.5 inches; head, neck, and upper parts of body brownish 

 black, becoming browner on forehead and jugulum ; wings and tail 

 more decidedly black; throat with a white patch, more or less 

 obscured by the superficial dark color prevailing elsewhere on the 

 fore-neck; breast and abdomen white; lower tail-coverts white 

 and cinereous mixed; tarsi yellowish brown; toes and webs chiefly 

 yellowish brown basally, and black terminally; bill black. 



From the foregoing description, it is seen that the characters of 

 Dr. Streets's specimens agree well with those set forth in Latham's 

 description, quoted above. The coloration of the plumage coin- 

 cides, and also the length of the commissure. That Latham 

 measured the commissure, and not the culmen, is revealed by the 

 length of bill given by him in species now well known; for example, 

 'bill is two inches long' in the 'Fulmar Petrel ' (Fulmarus gladalis) 

 and 'three quarters of an inch in length' in the 'Fork-tail Petrel' 

 (Oceanodroma furcata). The only disagreement between Dr. 

 Streets's specimens and Latham's description occurs in the color 

 of the tarsi, the light color in the specimens disagreeing with the 

 'black brown' in the description. The color of the tarsi, however, 

 is an unreliable character unless determined in life, or soon after 

 death; for light tarsi sometimes become dark in drying, as in certain 

 specimens of Pterodroma phceopygia and Pterodroma inexpectata. 



It seems reasonable to conclude, from the evidence presented, 

 that the White-breasted Petrel of Latham, Procellaria alba Gmelin, 

 and Procellaria parvirostris Peale relate to one and the same spe- 

 cies, which according to current rules of nomenclature should bear 

 the name of Pterodroma alba (Gmelin) . 2 



i Cf. Streets, Bull. U. S. Nat. Mus. No. 7, 1S77, pp. 8, 30; Man. N. A. Birds, 1887, p. 65. 



2 Other authors have sought a solution of Procellaria alba Gmelin in Pterodroma incerla, 

 P. neglecta, and P. ' arminjoniana.' Cf. Coues, Proc. Acad. Nat. Sci. Phila., 1866, pp. 143, 

 144, 147, 194; Salvin, Bowley's Orn. Misc., Vol. I, 1876, p. 234, Cat. Birds Brit. Mus., 

 Vol. XXV, 1896, p. 412; Godman, Monogr. Petrels, 1908, p. 226; Mathews & Iredale, 

 Ibis, 1913, p. 231; Brabourne and Chubb, Birds S. Amer., Vol. I, 1912, p. 31. 



